64 lines
1.6 KiB
C++
64 lines
1.6 KiB
C++
namespace factor
|
|
{
|
|
|
|
/* Assembly code makes assumptions about the layout of this struct:
|
|
- callstack_top field is 0
|
|
- callstack_bottom field is 1
|
|
- datastack field is 2
|
|
- retainstack field is 3 */
|
|
struct context {
|
|
/* C stack pointer on entry */
|
|
stack_frame *callstack_top;
|
|
stack_frame *callstack_bottom;
|
|
|
|
/* current datastack top pointer */
|
|
cell datastack;
|
|
|
|
/* current retain stack top pointer */
|
|
cell retainstack;
|
|
|
|
/* saved contents of ds register on entry to callback */
|
|
cell datastack_save;
|
|
|
|
/* saved contents of rs register on entry to callback */
|
|
cell retainstack_save;
|
|
|
|
/* callback-bottom stack frame, or NULL for top-level context.
|
|
When nest_stacks() is called, callstack layout with callbacks
|
|
is as follows:
|
|
|
|
[ C function ]
|
|
[ callback stub in code heap ] <-- this is the magic frame
|
|
[ native frame: c_to_factor() ]
|
|
[ callback quotation frame ] <-- first call frame in call stack
|
|
|
|
magic frame is retained so that it's XT can be traced and forwarded. */
|
|
stack_frame *magic_frame;
|
|
|
|
/* memory region holding current datastack */
|
|
segment *datastack_region;
|
|
|
|
/* memory region holding current retain stack */
|
|
segment *retainstack_region;
|
|
|
|
/* saved userenv slots on entry to callback */
|
|
cell catchstack_save;
|
|
cell current_callback_save;
|
|
|
|
context *next;
|
|
};
|
|
|
|
#define ds_bot (ctx->datastack_region->start)
|
|
#define ds_top (ctx->datastack_region->end)
|
|
#define rs_bot (ctx->retainstack_region->start)
|
|
#define rs_top (ctx->retainstack_region->end)
|
|
|
|
DEFPUSHPOP(d,ds)
|
|
DEFPUSHPOP(r,rs)
|
|
|
|
VM_C_API void nest_stacks(stack_frame *magic_frame, factor_vm *vm);
|
|
VM_C_API void unnest_stacks(factor_vm *vm);
|
|
|
|
}
|
|
|